Scalable Synthesis of Low-Pt PtCu<sub>3</sub> Intermetallic Oxygen Reduction Electrocatalysts via Sulfur-Containing Inorganic Salt-Assisted Strategy
Shi‐Long Xu, Peng Yin, Lu‐Jie Zuo, Shi-Yi Yin, Yue Lin, Wanqun Zhang, Shengqi Chu, Hai‐Wei Liang, Xian‐Zhu Fu
Abstract
Proton exchange membrane fuel cells (PEMFCs) as electrochemical-generating devices with zero contaminants can promise a carbon-neutral future, but the usage of the costly platinum group metal catalysts hindered the widespread adoption of PEMFCs. Here, we present the synthesis of a highly active low-Pt PtCu 3 intermetallic oxygen reduction catalyst via a sulfur-containing inorganic salt-assisted strategy. We identify that the success of the catalyst synthesis lies in the use of inorganic negative bivalent sulfur salts that leads to the formation of the CuS 2 intermediate at low temperatures. The CuS 2 intermediate serves as a passivator and releases Cu source at high temperatures to facilitate the formation of the PtCu 3 intermetallic catalyst. The prepared small-sized PtCu 3 intermetallic catalyst exhibits a high mass-based activity of 3.0 A mg Pt –1 and a large electrochemically active surface area of 74 m 2 g Pt –1 for oxygen reduction, along with an outstanding durability (18% mass activity loss after 30,000 cycles).